[Dyspnea and palpitations in a 39-year-old male patient]. / Kurzatmigkeit und Herzstolpern bei einem 39-jährigen Patienten.

A 39-year-old male patient presented with dyspnea and palpitations. The electrocardiogram (ECG) showed a first degree atrioventricular (AV) block and frequent atrial extra systoles. Within the following 48 h the AV block gradually developed into a third degree intermittent complete AV block. The patient history included an untreated tick bite 2 months before presentation. The serological proof of antibodies confirmed the diagnosis of Lyme carditis and antibiotic treatment with ceftriaxon i.v. was initiated. Normal AV conduction finally resumed and the symptoms subsided completely without any further clinical consequences.

Long-term left atrial remodeling after ablation of persistent atrial fibrillation: 7-year follow-up by cardiovascular magnetic resonance imaging.

PURPOSE: Restoration of sinus rhythm in patients with persistent atrial fibrillation (ps. AF) induces reverse atrial remodeling and improvement of left ventricular function. We evaluated the effect of ablative treatment on cardiac remodeling after a long follow-up period of 7 years by cardiovascular magnetic resonance (CMR). METHODS: Patients with symptomatic ps. AF underwent CMR within 7 days prior to the ablation procedure. Left atrial and ventricular volumes were measured. All patients underwent circumferential pulmonary vein isolation. At the end of follow-up (FU), a CMR and 7-day ECG registration were performed. RESULTS: Forty-two patients (67 ± 9 years) were included. After a FU of 86 ± 13 months, 23 patients had a successful outcome. In these patients, LVEF improved from 56 ± 5 to 62 ± 4% (p = 0.02), but left atrial volume and ejection fraction (LAV, LAEF) remained unchanged (105 ± 25 to 98 ± 34, p = 0.44; 34 ± 10 to 36 ± 11, p = 0.6, respectively). In 14 patients with a BMI < 30 and no left ventricular hypertrophy (LVH), LAV decreased (104 ± 30 to 82 ± 26 ml, p = 0.01) and LAEF improved (33 ± 12 to 40 ± 11%, p = 0.03). In 9 patients with successful outcome and either BMI ≥ 30 or LVH, LAV increased (110 ± 26 to 125 ± 30 ml, p = 0.03) and LAEF deteriorated (35 ± 11 to 31 ± 10%, p = 0.04). CONCLUSIONS: Successful ablative treatment of atrial fibrillation is associated with reverse left atrial remodeling and improvement of left atrial and ventricular function. In patients with a BMI ≥ 30 or left ventricular hypertrophy, further left atrial enlargement occurs despite successful outcome.

Updated Survey on Interventional Electrophysiology: 5-Year Follow-Up of Infrastructure, Procedures, and Training Positions in Germany.

OBJECTIVES: This study provides an update and comparison to a 2010 nationwide survey on cardiac electrophysiology (EP), types and numbers of interventional electrophysiological procedures, and training opportunities in 2015. BACKGROUND: In 2010, German cardiology centers performing interventional EP were identified and contacted to provide a survey on cardiac EP. METHODS: German cardiology centers performing interventional EP in 2015 were identified from quality reports and contacted to repeat the 2010 questionnaire. RESULTS: A majority of 131 centers (57%) responded. EP (ablation procedures and device therapy) was mainly part of a cardiology department (89%) and only independent (with its own budget) in 11%. The proportion of female physicians in EP training increased from 26% in 2010 to 38% in 2015. In total, 49,356 catheter ablations (i.e., 81% of reported ablations in 2015) were performed by the responding centers, resulting in a 44% increase compared with 2010 (the median number increased from 180 to 297 per center). Atrial fibrillation (AF) was the most common arrhythmia interventionally treated (47%). At 66% of the centers, (at least) 2 physicians were present during most catheter ablations. A minimum of 50 (75) AF ablations were performed at 80% (70%) of the centers. Pulmonary vein isolation with radiofrequency point-by-point ablation (62%) and cryoablation (33%) were the preferred ablation strategies. About one-third of centers reported surgical AF ablations, with 11 centers (8%) performing stand-alone surgical AF ablations. Only one-third of the responding 131 centers fulfilled all requirements for training center accreditation. CONCLUSIONS: Comparing 2010 with 2015, an increasing number of EP centers and procedures in Germany are registered. In 2015, almost every second ablation was for therapy for AF. Thus, an increasing demand for catheter ablation is likely, but training opportunities are still limited, and most centers do not fulfil recommended requirements for ablation centers.

[AV nodal reentrant tachycardia. Diagnosis and therapy]. / AV-Knoten-Reentrytachykardie. Diagnostik und Therapie.

The AV nodal reentrant tachycardia (AVNRT) is one of the most common arrhythmias encountered in clinical practice. It is characterized by a constant heart rate and an on/off phenomenon. The clinical symptoms may include palpitations, anxiety, polyuria, and dyspnea. Typically, tachycardia may be disrupted by vagal maneuvers in many patients. First-line treatment of symptomatic AVNRT is radiofrequency ablation. The present article deals with the characteristics, differential diagnosis and treatment of AVNRT in the EP lab. It is the second part of a series of manuscripts which may facilitate further education in the specific field of electrophysiology.

Fast atrial activity predicts recurrence of atrial fibrillation after pulmonary vein isolation: results from a prospective randomized study.

BACKGROUND: Recurrence of atrial fibrillation (AF) after ablative treatment is common. We hypothesized that AF recurrence is heralded by fast ectopic atrial activity occurring after electrical reconnection of previously isolated pulmonary veins. METHODS: Patients with paroxysmal or persistent AF undergoing pulmonary vein isolation (PVI) were followed up by 24-h Holter monitoring every 3 months for the first year and every 6 months thereafter. Antiarrhythmic drugs were withdrawn after a blanking period of 4 weeks for paroxysmal and 3 months for persistent AF. Ectopic atrial activity was defined as a burden of atrial extrasystoles >5% of the total QRS number. Fast atrial activity was present if mean cycle length of ectopic atrial activity was shorter than 50% of the mean cycle length of sinus rhythm in the last ten heartbeats. Patients with symptomatic fast atrial activity but without AF recurrence were randomized to undergo a second PVI procedure or resume antiarrhythmic medication. During follow-up, a 24-h Holter recording was performed every 3 months. Additionally, a 7-day external loop recording was performed in every pt with palpitations and no AF or ectopic atrial activity in the 24-h Holter. RESULTS: One hundred twenty-four pts with AF (88 paroxysmal, 36 persistent) developed fast atrial activity 6 ± 3 months after PVI. Twenty-two pts were asymptomatic and eight pts refused randomization. Ninety-four pts (61 men, age 57 ± 12 years) were randomized to either receive a second PVI procedure (group I, 48 pts) or antiarrhythmic medication (group II, 46 pts). Re-PVI in group I was performed 10 ± 8 months after the first PVI. During a follow-up of 20 ± 6 months, 11 pts of group I (23%) and 43 pts of group II (93%) had recurrence of AF. The mean time of AF recurrence after appearance of fast atrial activity was 4 ± 2 in group I and 5 ± 3 months in group II. CONCLUSIONS: In patients with atrial fibrillation and after the first PVI procedure, appearance of symptomatic fast atrial activity is associated with a high risk of AF recurrence. Re-isolation of reconnected pulmonary veins in these pts significantly reduces the risk of AF recurrence.

Three-dimensional rotational venography of the coronary sinus tree facilitates left ventricular lead implantation for CRT.

BACKGROUND: Precise knowledge of the coronary sinus (CS) tree anatomy facilitates catheter-based intubation of the CS, target vein and lead selection and reduces the need for fluoroscopy, contrast medium and overall procedure time in cardiac resynchronization therapy (CRT). Three-dimensional rotational angiography (3DRA) provides a new means of multiangle imaging of the CS tree that can be applied preoperatively. PURPOSE AND METHODS: Our study aims to investigate the feasibility of preoperative rotational CS venography and its implications for CRT device implantation procedures. For this purpose, CS visualization was done either conventionally with retrograde CS venography and standard fluoroscopic views (SFV, n = 30), or with antegrade CS imaging via contrast medium injection into the left coronary artery using 3DRA in the venous phase of contrast flow (3DRA, n = 30). RESULTS: 3DRA successfully identified the posterior and left marginal veins in 92% of patients and allowed target vein visualization in 86%. Additional retrograde venography was necessary in four patients (14%). Fluoroscopy time and contrast medium administration for stable CS intubation were lower in the group with 3DRA than in those with SFV (all p < 0.05). The time for CS lead placement after guiding catheter intubation was 8.9 ± 5.5 min in the 3DRA group versus 14.7 ± 7.4 min in SFV patients (p < 0.05). Consequently, total fluoroscopy time (-12.1 min), volume of contrast medium (-29.5 ml) and overall procedure time (-32.8 min) were significantly lower in 3DRA than in SFV patients (p < 0.05). CONCLUSION: 3DRA offers reliable multiangle visualization of the CS anatomy and facilitates successful CRT lead implantation.

Second generation of cryoballoons can improve efficiency of cryoablation for atrial fibrillation.

BACKGROUND: We investigated whether the new second generation of cryoballoons can improve the efficiency and safety of cryoablation for atrial fibrillation (AF) during ablation and in terms of outcome. METHODS: Data of AF patients consecutively treated with a single 28-mm cryoballoon were analyzed. Patients were divided into two groups: the G1 group was treated with the first-generation cryoballoons (ArcticFront) and G2 with the second generation (ArcticFront Advance). Failure of cryoablation treatment was defined as detection of an episode of AF, atrial flutter, or atrial tachycardia lasting ≥ 30 seconds during 3-month follow-up. Left atrial diameter (LAD) was measured by transthoracic echocardiography before cryoablation. RESULTS: One hundred twenty-five patients (group G1/G2: 57/68) were enrolled. Mean total time of the whole procedure, cryomapping, and cryoablation was shorter with G2 than with G1 (P < 0.05). No complication occurred with G1 whereas with G2 the complication rate was 8.8%. During mean 12 ± 4 months follow-up, the overall success rate of cryoablation was 76.0% (95/125); it was higher with G2 (89.7% [61/68] vs 59.7% [34/57], P < 0.001). Patients in whom treatment failed had larger LAD (48 ± 8 mm vs 44 ± 6 mm, P = 0.002) than those in whom it succeeded. Type of cryoballoon (relative risk [RR] = 5.75 [2.16, 15.27], P < 0.0001) and LAD (RR = 0.90 [0.83, 0.97], P = 0.0043) were shown in multivariable analysis to be individually related to the difference in success rate. CONCLUSION: Ablation for AF with the new generation of cryoballoons is associated with higher success rate of pulmonary vein isolation and better outcome. However, more complications occurred during the early stage of application of the G2 cryoballoon.

Diagnosis and management of atrial fibrillation: an overview.

Atrial fibrillation (AF) has been defined as the new cardiovascular "epidemic". Its prevalence is rising in developed countries, and the associated social and economic costs are high. In the last few years, there has been an increasing interest in understanding the mechanisms of AF and its management. New pharmacotherapies together with novel techniques for surgical and catheter treatment of AF have been developed, allowing the maintenance of sinus rhythm and the alleviation of symptoms in a large number of patients with AF. However, there are still some challenges that need to be addressed. This article gives an overview of the current state of the art on novel techniques for diagnosis and management of AF.

Prolonged ablation on critical segments of pulmonary vein ostia in paroxysmal atrial fibrillation: a prospective randomized controlled study.

INTRODUCTION: Electrical reconnection of the pulmonary veins (PVs) plays a key role in the recurrence of atrial fibrillation (AF) after ablative treatment. This randomized controlled study tested the hypothesis that prolonged ablations, on areas that may be critical for left atrial (LA)-PV conduction, can significantly reduce the rate of acute PV reconnection and AF recurrence. METHODS: Patients with paroxysmal AF were randomly assigned to either a control or an add-on group.Ostial PV isolation (PVI) was performed by point-to-point RF ablation (irrigated tip, 30 Watts, 30 seconds).An ostial segment was assumed to be critical for LA-PV connection if any of the following reactions occurred during RF application: (1) sudden delay of LA-PV conduction, (2) change of activation sequence,and (3) PVI. In this case, RF application was prolonged from 30 seconds to 90 seconds in the add-on group only. RESULTS: A total of 131 patients (58 ± 11 years, 47 female) were assigned to a control (n = 64) and an add-on (n = 67) group. Ablation time was longer in the add-on (48 ± 16 minutes vs 37 ± 15 minutes, P = 0.03). Acute PV reconnection was observed in 20 of 64 controls and in eight of 66 add-on patients (31% vs 12%, P < 0.001). During a follow-up of 26 months, AF recurred in 33 of 64 controls and in 16 of 66 add-on patients (52% vs 24%, P = 0.001) after a single ablation procedure. CONCLUSIONS: Prolonged radiofrequency application on critical segments of LA-PV connection is a safe and effective ablative strategy that significantly reduces acute PV reconnection and AF recurrence rates after a single ablation procedure for paroxysmal AF.

Precordial electrode placement for optimal ECG monitoring: implications for ambulatory monitor devices and event recorders.

INTRODUCTION: Detection of QRS complexes, P-waves and atrial fibrillation f-waves in electrocardiographic (ECG) signals is critical for the correct diagnosis of arrhythmias. We aimed to find the best bipolar lead (BL) with the highest signal amplitude and shortest inter-electrode spacing. METHODS: ECG signals (120 seconds) were recorded in 36 patients with 16 precordial electrodes placed in a standardized pattern. An average signal was analysed for each of 120 possible BLs obtained by calculating the difference between pairs of unipolar leads. Peak-to-peak amplitudes of QRS waves (50ms around R-peak) and P waves (270-70ms before R-peak) were calculated. For patients with atrial fibrillation, power of the fibrillatory (f) wave was used instead. Maximum values at each distance were considered and differentiation analysis was performed based on incremental changes (amplitude to distance). RESULTS: There was a significant correlation between distance and QRS-amplitude (r=0.78, p<0.001), P-wave amplitude (r=0.60, p<0.01) and f-wave power (r=0.79, p<0.001). The range of values was: QRS-amplitude 0.7-2.33mV, P-wave amplitude 0.07-0.18mV, and f-wave power 0.55-2.12mV(2)/s. The maximum value for the shortest distance was on a heart-aligned axis over the left ventricle for the QRS complex (1.9mV at 8.7cm) and over the atria for the P-wave (0.98mV) and f-waves (1.45mV(2)/s at 8cm, respectively). CONCLUSION: There is a strong positive correlation between electrode distance and ECG signal-amplitude. Distance of 8cm on a heart-aligned axis and over the relevant heart-chamber provides the highest signal amplitude for the shortest distance. These findings are essential for the design and use of ambulatory monitoring devices.

Long-term follow-up outcome of single cryoballoon ablation for atrial ifbrillation / 中国介入心脏病学杂志

Objective To analyse long-term follow-up outcome of cryoballoon ablation (CBA) for atrial ifbrillation (AF) in a single center and to investigate the clinical relative factors which affecting the effect. Methods The inpatient, operating and outpatient data of patients, who were treated by CBA for AF in our center from January 2009 to April 2013, were retrospectively analyzed. Left atrium diameter (LAD) was measured by transthoracic echocardiography. Failure-treatment of CBA was defined by episode of AF, atrial lfutter, atrial tachycardia lasted for 30 seconds after 3 months. Results A total of 199 patients were enrolled. The rates of phrenic nerve paralysis, pericardial effusion, transient ischemic attack were 1.5%(n=3), 0.5%(n=1), 0.5%(n=1),respectively. All complications were resolved spontaneously.152 patients had completed follow-up data after ifrst-time CBA during a long-term follow-up of mean 23±14 months, 65 patients (42.8%) treated success. 75 patients with failure-treated were (86.2%) experienced the atrial arrhythmia recurrence in ifrst 12 month. The characteristics of failure-treated patients included with older age[(62±7) years vs. (52±10) years, P=0.0379]and larger LAD[(48±6)mm vs. (43±6) mm, P<0.0001]. The Logistic analysis showed that LAD[OR=0.896(0.842,0.953), P=0.005]and age[OR=1.037 (1.000,1.076), P=0.0488]could individually predict the treat-failure after ifrst CBA, and only LAD[OR=0.876 (0.822,0.935), P < 0.0001]could individually predict the total CBA. Conclusions CBA procedure for AF is safe and effective, and the result of long-term follow-up is preferable. Most atrial arrhythmia are recurred during ifrst 12 month after CBA. LAD can individually predict the failure in treatment of CBA.

A survey of German centres performing invasive electrophysiology: structure, procedures, and training positions.

AIMS: To provide a nationwide survey (and reference for the future) on cardiac electrophysiologists, types and numbers of invasive electrophysiological procedures, and training opportunities in 2010. METHODS AND RESULTS: German cardiology centres performing invasive electrophysiology were identified from quality reports and contacted to fill a questionnaire. A majority of 122 centres (65%) responded. Electrophysiology (ablation procedures and device therapy) was mainly part of a cardiology department (82%), and only in 9% independent (own budget). In only 58% of the centres, (at least) two physicians were present during catheter ablations. Although in 2010, women represented 59.4% of physicians <35 years old, only 26% of physicians in electrophysiology training were female. In total, 33 420 catheter ablations were performed with a median number of 180 per centre. Atrial fibrillation (AF) was the most common arrhythmia invasively treated (35%). At least 50 AF ablations were performed in 53% of the centres. Of the centres performing AF ablations, consecutive left atrial arrhythmias were treated by catheter ablation only in 75%, and only 44% had in-house surgical backup. Only one-fourth of the 122 centres fulfilled all requirements for training centre accreditation according to the European Heart Rhythm Association and the German Cardiac Society. CONCLUSION: The results indicate a high number of electrophysiology centres and procedures in Germany. Atrial fibrillation was the most common arrhythmia invasively treated. An increasing demand for catheter ablation is likely, but training opportunities are limited. Women are clearly underrepresented. A co-operation of higher and lower volume electrophysiology centres may be necessary for training purposes.

Combined use of three-dimensional rotational angiogram of left atrium and circular multi-electrode ablation catheter for pulmonary vein isolation.

BACKGROUND: A novel circular pulmonary vein ablation catheter (PVAC) has been introduced for pulmonary vein isolation (PVI). Accurate delineation of left atrium-pulmonary vein (LA-PV) anatomy is important for this technique. The aim of this study was to test whether the 3-dimensional rotational angiography (3D RTA) of the left atrium can facilitate PVI using PVAC technique. METHODS: Twenty patients with paroxysmal atrial fibrillation (AF) were enrolled in this study. The 3D RTA was reconstructed and registered with live fluoroscopy in all the patients. AF ablation was performed with a PVAC catheter in the navigation of registered 3D RTA. RESULTS: The 3DRTA image was successfully reconstructed and registered with live fluoroscopy in all patients (100%). The LA-PV anatomy was delineated clearly in all patients. Navigation of the PVAC inside the registered 3D RTA, ensured accurate placement within the atrium to perform ablation, and the PVAC was correctly placed inside the PV ostium to verify the PVI. All the PVs were isolated. Total procedural time was (87.5 ± 12.1) minutes, and fluoroscopy time was (20.1 ± 6.3) minutes. Follow-up after (7.1 ± 1.5) months showed freedom from AF in 70% (14/20) patients. No PV stenosis was observed. CONCLUSIONS: Intraprocedure reconstructed and registered 3D RTA can clearly delineate the LA-PV anatomy in real-time. The results demonstrate the feasibility and reliability of combining use of 3DRA and PVAC in AF ablation procedures.

Oxygen Kinetics and Heart Rate Response during Early Recovery from Exercise in Patients with Heart Failure.

Background. The purpose of this study was to assess the post-exercise O(2) uptake and heart rate response in patients with heart failure (HF) in comparison to healthy individuals. Methods and Results. Exercise testing of all subjects was conducted according to the RITE-protocol. The study subjects were classified according to their peak oxygen uptake (peak VO(2)) in four groups: healthy individuals with a peak VO(2) >22 mL/kg/min (group 1, n: 50), and patients with HF and a peak VO(2) of 18-22 mL/kg/min, (group 2, n: 48), 14-18 mL/kg/min (group 3, n: 57), and <14 mL/kg/min (group 4, n: 31). Both peak VO(2) and HR declined more slowly in the patients with HF than in the normal subjects. Recovery of VO(2) and HR followed monoexponential kinetics in the early post-recovery phase. This enabled the determination of a time constant for both HR and VO(2) (TC VO(2) and TC HR). From group 1 to 4 there was a prolongation of the time constant for VO(2) and HR: TC VO(2) (group 1: 110 ± 34, group 2: 197 ± 43, group 3: 238 ± 80, and group 4: 278 ± 50 sec), and TC HR (group 1: 148 ± 82, group 2: 290 ± 65, group 3: 320 ± 58, and group 4: 376 ± 55 sec). Conclusion. The rate of decline of VO(2) and HR in the early post-exercise phase is inversely related to the peak VO(2). The time constant for oxygen uptake (TC VO(2)) and heart rate (TC HR) might prove a useful parameter for more precise monitoring and grading of HF.

Predictive value of left atrial volume measured by non-invasive cardiac imaging in the treatment of paroxysmal atrial fibrillation.

PURPOSE: We investigate the role of left atrial volume (LAV) as a predictor of outcome following pulmonary vein isolation (PVI) in patients with exclusive paroxysmal atrial fibrillation (AF). METHODS: PVI was performed in 213 patients (80 females, aged 60 ± 10 years) with paroxysmal AF using either the pulmonary vein ablation catheter (PVAC, n = 78) or conventional single-tip ablation (n = 135). LAV was assessed by multi-detector computed tomography (n = 39) or cardiac magnetic resonance imaging (n = 174) prior to ablation. LA diameter (LAD) and LA area were determined by echocardiography. Patients were followed up for 12 months clinically and with 72-h Holter ECG. RESULTS: The mean LAV was 85 ± 28 ml (range, 22-189 ml). Mean LAD and mean LA area were 43 ± 6 mm and 23 ± 6 cm². After a follow-up period of 18 ± 5 months, 202 patients were analyzed. AF recurrence was documented in 50 (23%) patients. Univariate analysis showed age (59 ± 11 vs. 65 ± 6 years, p = 0.049), LA area (23 ± 5 vs. 27 ± 6 cm², p = 0.03), and LAV (80 ± 27 vs. 96 ± 28 ml, p = 0.04) to be significantly associated with the outcome. Multivariate analysis revealed that none of these parameters were statistically significant (hazards ratio LAV, 0.52-1.12, p = 0.058; LA area, 0.63-1.14, p = 0.069; and age, 0.90-1.09, p = 0.41). In the case of AF recurrence, patients with LAV >95 ml showed a significantly higher probability for the occurrence of persistent AF (24% vs. 8%, p = 0.02). CONCLUSIONS: The assessment of LA size should not be incorporated as a main factor with regard to predicted ablation success in patients with paroxysmal AF being considered for PVI, as PVI may be successful even with considerable LA enlargement. Ablation should be performed promptly in patients with LAV ≤ 95 ml to prevent further LA dilatation, as patients with LAV >95 ml have an increased probability to develop persistent AF in the case of ablation failure.

Characteristic changes of volume and three-dimensional structure of the left atrium in different forms of atrial fibrillation: predictive value after ablative treatment.

INTRODUCTION: Atrial fibrillation (AF) is associated with electroanatomical remodelling of the left atrium (LA), especially with LA dilatation. However, little is known about the changes of the three-dimensional structure of the LA, regarding the type of atrial fibrillation and their prognostic value after an ablative treatment. METHODS: One hundred fifteen patients (72 males, 59 ± 11 years) with an indication for AF ablation were prospectively included. Preoperatively, all patients underwent cardiac computed tomography (CCT). A reconstruction of the LA and the pulmonary veins (PV) was made from CCT data using specialized software (EP PreNavigator, Philips, The Netherlands). Left atrial volume (LAV) after exclusion of the atrial appendage (LAA) and the PV was determined. The LA was then arbitrarily divided by a cutting plane, between the anterior segment of the PV ostia and the atrial appendage and parallel to the posterior wall, to anterior-(LA-Ant.) and posterior-LA (LA-Post.). The ratio LA-Ant./LAV was defined as asymmetry index (ASI). The cardiac CT data, of 25 patients (11 women, 47 ± 11 years) without organic heart disease, were similarly studied for the same parameters, as a control group. RESULTS: Patients with paroxysmal AF (n = 63) had significantly higher LAV (131 ± 31 vs. 95 ± 18 ml, p < 0.001) and higher ASI (61 ± 6 % vs. 57 ± 4, p = 0.002) than the control group. Patients with persistent AF (n = 34) in comparison with paroxysmal AF showed significantly larger volumes (154 ± 44 vs. 131 ± 31 ml, p = 0.007) but no difference in the ASI (60 ± 8% vs. 61 ± 6%, p = 0.63). Finally, patients with long-term persistent AF (n = 18) showed a bigger asymmetry index than the patients with persistent AF (64 ± 5% vs. 60 ± 8%, p = 0.06) but no significant difference in volumes (161 ± 21 vs. 154 ± 44 ml, p = 0.49). LAA and partial LA volumes had a dilatation pattern similar to LAV. During a follow-up of over 25 ± 7 months, AF recurred in 31 (27%) patients. Multivariate analysis showed that ASI and LAV were the only two significant predictors of AF recurrence after ablative treatment. Independent of LAV, an ASI over 60% predicted AF recurrence with 74% sensitivity and 73% specificity. CONCLUSION: Characteristic differences of both left atrial volume and geometry exist between the different forms of atrial fibrillation (paroxysmal, persistent and long-term persistent). The asymmetry index is a simple parameter derived by cardiac CT data that reflects these changes of LA geometry and predicts the outcome after the pulmonary vein isolation.

Frequency analysis of atrial fibrillation surface and intracardiac electrograms during pulmonary vein isolation.

AIMS: Frequency analysis of atrial electrograms from patients diagnosed with persistent atrial fibrillation (AF) appears to be crucial in its clinical diagnosis. This work explores the fibrillatory frequency properties of both surface and intracardiac electrograms before and after pulmonary vein isolation (PVI) using three time-frequency techniques. METHODS AND RESULTS: Surface electrocardiograms (ECGs) of 21 patients diagnosed with persistent AF undergoing PVI were recorded. Three methods, Fourier, ensemble average, and wavelet analysis, were used to identify the dominant frequency (DF) in surface ECGs. Dominant frequency was also computed in electrograms recorded within the coronary sinus (CS). Dominant frequency measured within the CS was best estimated in surface lead V1 using both Fourier (relative error: 10.94 ± 10.37%, correlation: 0.58) and wavelet analysis (relative error: 10.97 ± 11.08%, correlation: 0.53). Ensemble average gave highest relative error (21.29 ± 18.07%) and lowest correlation (0.10). Dominant frequency decreased after right PVI. This decrease was significant (P< 0.05) in most of the patients (13, 14, and 7 out of 14 when Fourier, wavelets, and ensemble average was used; 14 in CS). Further isolation of the left pulmonary veins (PVs) yielded a significant (P< 0.05) decrease in only a few of them (3, 4, and 2 out of 14 when Fourier, wavelets, and ensemble average was used; 4 in CS). CONCLUSION: Wavelet and Fourier analysis are good tools for estimating the atrial fibrillatory rate from surface ECG. A drop was observed in the DF value after isolation of the right PV. However, after left PVI this decrease was smaller.

Cardiovascular magnetic resonance imaging for accurate sizing of the left atrium: predictability of pulmonary vein isolation success in patients with atrial fibrillation.

PURPOSE: To prospectively determine the most reproducible approach for left-atrial size assessment using cardiovascular magnetic resonance (CMR) imaging in patients with atrial fibrillation and its value for prediction of pulmonary vein isolation (PVI) treatment success. MATERIALS AND METHODS: Eighty patients underwent CMR imaging prior to PVI; the CMR examination included standard cine sequences, a multislice cine sequence in 4-chamber orientation with full left-atrial coverage, and a contrast-enhanced MR angiography of the left atrium. Left-atrial size was determined as: diameter, area, volume segmented from angiography, and diastolic/systolic volumes from cine imaging (Simpson's rule). All measurements were carried out by two independent observers and repeated by one observer to assess inter- and intrareader variability. Treatment success was defined as persisting sinus rhythm after PVI (follow-up period 12.6 ± 6.6 months). RESULTS: All left-atrial measurements showed substantial intrareader agreement. Interreader agreement was substantial for diastolic/systolic left-atrial volumes only. Calculated bias was found to be minimal (0.1%-4.9%). Predictability of PVI treatment success was best using cine volumetric measurements (cutoff value for diastolic volume, 112 mL) yielding a sensitivity and specificity of 80% and 70%, respectively. CONCLUSION: Left-atrial volumetry based on cine imaging represented the most reproducible approach to determine left-atrial size. PVI success was predicted best using cine volumetry.